A disk cartridge, for example, a magnetic disk cartridge, mainly comprises a cartridge case having openings for inserting magnetic heads and openings for inserting a rotation driving shaft, a flexible magnetic disk rotatably encased in the cartridge case, and a cleaning sheet supported on the inside surfaces of the cartridge case.
The cleaning sheet for the conventional magnetic disk cartridge is composed of a non-woven fabric made of, for example, mixed-fibers of rayon and polypropylene, mixed fibers of rayon and polyethylene terephthalate, or single fibers of polyethylene terephthalate, and is fixed to the inside surfaces of a cartridge case by ultrasonic welding, heat seal, or by an adhesive.
However, the cleaning sheets composed of the fibers do not perform good cleanability of the magnetic disk, and further have such problems as the development of scratches on the magnetic disk surface by sliding contact with the cleaning sheet, falling-away of the fibers from the cleaning sheet by sliding contact with the magnetic disk, and attachment of the falling-away fibers to the magnetic disk or the magnetic head, thereby adversely affecting the recording-reproducing characteristics.